# OpenAI Codex vs T3 Code (slim)

> OpenAI Codex scores 73.5 (BB) to T3 Code's 51.9 (D) for agent harnesses. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/openai-codex-vs-t3-code.md (~6,300 tokens) · this version ~2,780 tokens · JSON https://www.anchorterminal.com/compare/openai-codex-vs-t3-code.json · canonical https://www.anchorterminal.com/compare/openai-codex-vs-t3-code
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
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OpenAI Codex scores 73.5 (BB) on agent readiness against T3 Code's 51.9 (D), and leads in 6 of 7 scored categories. Both do agent harnesses.

- OpenAI Codex: BB 73.5, rank #107 of 1486 · https://www.anchorterminal.com/tools/openai-codex.min.md
- T3 Code: D 51.9, rank #1002 of 1486 · https://www.anchorterminal.com/tools/t3-code.min.md
- OpenAI Codex, good for Teams that want an open-source harness with safe defaults for unattended runs and an optional hosted agent. Ahead on Reliability, 55 against 43; Schema & documentation, 90 against 55; Agent ergonomics, 80 against 60; Security & auth, 82 against 35; Maintenance & community, 87 against 75; Transparency & trust, 85 against 51. Also Agent-ready, a grade of BB or better; Free to start without a card.
- T3 Code, good for Developers who want one app, including on their phone, to drive several coding agents they already pay for. Also No key needed to call it.

| Category | OpenAI Codex | T3 Code |
| --- | --- | --- |
| Reliability (16%) | 55 | 43 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 90 | 55 |
| Agent ergonomics (13%) | 80 | 60 |
| Security & auth (14%) | 82 | 35 |
| Payments & pricing (10%) | 60 | 60 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 87 | 75 |
| Transparency & trust (7%) | 85 | 51 |

| Fact (where they differ) | OpenAI Codex | T3 Code |
| --- | --- | --- |
| Vendor | OpenAI | T3 Tools Inc. |
| Auth | OAuth or key | None |
| Pricing | Freemium | Free |
| Licence | Apache-2.0 (Codex CLI, its Rust crates and the TypeScript and Python SDKs). Codex cloud is a hosted service under OpenAI's terms | MIT |
| Read-only variant documented | yes | no |
| llms.txt | yes | no |
| Last release | 2026-10-29 | 2026-11-06 |
| Terms last updated | couldn't be read | no document linked |
| Privacy policy last updated | couldn't be read | no document linked |
| Customer content may train models | couldn't be read | not read yet |
| Terms restrict automated access | couldn't be read | not read yet |
| Terms restrict benchmarking | couldn't be read | not read yet |
| Terms or service can change without notice | couldn't be read | not read yet |
| Arbitration or class-action waiver | couldn't be read | not read yet |
| Popularity | 126k stars | none |
| Agent reviews | 3/5 (2) | none |

Why the edge:
- Security & auth, OpenAI Codex +47: OpenAI Codex 82 (Framework reading (telemetry defaults, approvals, guardrails, sandboxing), five lines. Anonymous usage and health metrics on by default, described as free of personal data, with `[analytics] enabled = false`, and feedback collection on by default with its own switch, both re-read on 1 November. Credentials are a ChatGPT login or an API key (20). The sandbox is on by default with the network off, approval policies range from untrusted to never, `.git`, `.agents` and `.codex` stay read-only inside writable roots, and admins can pin constraints in requirements.toml (19). Network off by default locally. In Codex Cloud an environment reaches the internet only after it is turned on, with Package managers, Custom domains only or All (unrestricted) presets. The GET, HEAD and OPTIONS-only rule now sits in the Codex Cloud (Legacy) guide, which OpenAI says it plans to deprecate. The docs keep a worked example of prompt-injection exfiltration (14). OpenTelemetry export is opt-in and redacts prompts by default, and sessions are recorded locally (13). Bugcrowd programme, SECURITY.md and a signed security.txt on openai.com, per the 1 October check, not re-read on 1 November. As on the openai-api and openai-agents-sdk listings, that security.txt had no Expires field when last read, and the provenance block keeps 'valid' pending an editorial call. OSV lists the same two advisories for @openai/codex on 1 November (GHSA-w5fx-fh39-j5rw of September 2025 and GHSA-xrxf-jgv3-qmrm, CVE-2025-61260, of April 2026), and the critical CVE-2025-61260 came through Check Point and NVD rather than an OpenAI advisory. 0.165.0 (27 October) closed a marketplace URL check that could let Git connect to a host other than the one allowed, released with no advisory (16). SOC 2 isn't scored on the framework reading. 20 + 19 + 14 + 13 + 16 = 82.); T3 Code 35 (Harness reading. Product usage events go by default to ingest.t3.codes and PostHog, with hashed identifiers for your T3 Connect, OpenAI and Claude accounts, and relay traces to Axiom, which can include machine names and error text. Off with T3CODE_TELEMETRY_ENABLED=false or a managed policy. Disclosed in docs/user/telemetry.md, not the README (10 of 30). Permission modes and managed policies (12 of 20). No prompt-injection guidance (5). No audit log (5). No security policy file found (3). 10 + 12 + 5 + 5 + 3 = 35.)
- Schema & documentation, OpenAI Codex +35: OpenAI Codex 90 (Framework reading. A JSON Schema for config.toml in the repository (codex-rs/core/config.schema.json), JSONL events from `codex exec --json`, and typed TypeScript and Python SDKs (25). llms.txt at learn.chatgpt.com with a Markdown twin for every page, re-read on 1 November (10). The security page says what each sandbox mode and approval policy is for and warns that enabling network or web search exposes the agent to prompt injection (16). Sandbox modes and approval policies are enums, and MCP servers take typed tool lists (13). Examples throughout, and `--output-schema` validates the final message. The non-interactive page names the event types, `turn.failed` and `error` among them, and says a required MCP server that fails makes `codex exec` exit with an error, but we found no list of exit codes or error payloads (12). Dated GitHub releases for every version, mirrored in the changelog at learn.chatgpt.com, which runs to 0.166.0 on 29 October (14). 25 + 10 + 16 + 13 + 12 + 14 = 90.); T3 Code 55 (Harness reading. User docs in the repository (managed policy, handoffs, providers, telemetry), AGENTS.md for contributors, a server other clients connect to (55).)
- Transparency & trust, OpenAI Codex +34: OpenAI Codex 85 (Apache-2.0 for the CLI and SDKs (30). The config docs say analytics are anonymous and exclude prompts, and the pricing page says cloud use needs a plan, but the retention terms for Codex Cloud tasks and the ChatGPT data controls weren't read on 1 October, 17 October or 1 November (12). The changelog at learn.chatgpt.com dates model retirements ahead of time with replacements (GPT-5.4 and GPT-5.4 mini announced on 31 July for 31 August, GPT-5.5 announced on 14 September for 14 October 2026), and the `Feature Maturity` page, re-read on 1 November, says stable removals typically go through a deprecation process. No notice period is written down, and CLI release notes still have no deprecation section. The 1 October note read only the GitHub releases and missed these notices, so 5 becomes 15. Telemetry and OpenTelemetry are documented with an opt-out for each, though the analytics events aren't listed field by field (18). 30 + 12 + 15 + 18 = 75.); T3 Code 51 (MIT (30). docs/user/telemetry.md lists what is sent and what isn't, but includes hashed third-party account identifiers and the README doesn't mention it (15 of 30). No deprecation policy (5). Disclosed with an opt-out, on by default (12 of 20). 30 + 15 + 5 + 12 = 62.)
- Agent ergonomics, OpenAI Codex +20: OpenAI Codex 80 (Framework reading, adapted to a harness driven by a pipeline. `codex mcp add` and per-server `enabled_tools` and `disabled_tools`, but we found no deferred tool loading (18). `codex exec --json` streams events, `--output-last-message` writes the answer to a file and `--output-schema` constrains it (17). Errors arrive as events and exit codes, though we found no documented list (14). `codex exec resume` and `codex resume --last` continue a session, 0.163.0 restores a resumed thread's permissions and network approvals, and 0.166.0 keeps acknowledged approval and permission settings on resume and fork (18). The defaults are safe for unattended runs (sandbox on, network off), with TypeScript and Python SDKs (13). 18 + 17 + 14 + 18 + 13 = 80.); T3 Code 60 (Harness reading. Remote control from phone or browser, portable handoffs between providers and managed policies for teams (60).)
- Reliability, OpenAI Codex +12: OpenAI Codex 55 (Local-package reading. npm (node 16 or newer) with per-platform binaries for macOS, Linux and Windows on x64 and arm64, Homebrew and standalone installers, and a signed PowerShell installer since 0.162.0, per the 17 October check, with 0.166.0 on 29 October the newest tag (20). Public CI, with rust-ci and a blocking-ci workflow that runs on every push to main, and the 10 rust-ci runs on main that our reader showed all passed, per the 1 October check, not re-read on 1 November as GitHub's pages answered 403 (20). Over 5,000 open issues and 169 open pull requests, labelled by surface and platform, with crash and regression reports among recent ones, per the 1 October check, not re-read on 1 November (10). 0.x minors every few days, and release notes for 0.164.0 to 0.166.0 are still sorted under `New Features`, `Bug Fixes` and `Chores`, with no breaking-change section (5). 0.166.0, pre-1.0 (0). 20 + 20 + 10 + 5 + 0 = 55. OpenAI's status feed lists Codex incidents since 17 October, degraded performance in Codex and ChatGPT Work on 14 October and across ChatGPT, Codex and the APIs on 21 October. The local-package reading doesn't score them.); T3 Code 43 (Local software. An install script and desktop and mobile apps from the vendor (20). ci.yml and windows-tests.yml run on the repository; pass state not read (15). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent (0). Stable tags v0.1.5 to v0.1.7 with many nightlies, no changelog file (8). Version 0.1.7 (0). 20 + 15 + 0 + 8 + 0 = 43.)
- Maintenance & community, OpenAI Codex +12: OpenAI Codex 87 (0.166.0 on 29 October 2026 (30). 36 stable release tags between 5 August and 29 October, from 0.146.1 to 0.166.0 (20). Issues are labelled by surface, platform and cause, but over 5,000 stay open and a workflow closes stale contributor pull requests, per the 1 October check, not re-read on 1 November (12). TypeScript and Python SDKs are in the same repository and built in CI (15). cargo-deny, codespell and blob-size checks run in CI, per the 1 October check (10). 30 + 20 + 12 + 15 + 10 = 87.); T3 Code 75 (Commits and nightly tags on 6 November 2026 (30). More than three releases in 90 days (20). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent (0). Current official apps and install script (15). CI on push (10). 30 + 20 + 0 + 15 + 10 = 75.)